PARASITES OF THE JAPANESE SHREW MOLE, UROTRICHUS TALPOIDES TEMMINCK

Seven specimens of the Japanese shrew mole, Urotrichus talpoides TEMMINCK, from central Japan were examined. A new nematode, Thominx urotrichi n. sp., was described from the mucosae of the mouth (tongue, palate and cheeks), the pharynx and an upper third of the esophagus. This nematode was characterized by long spicule and spicular sheath, and minute round depressions of the egg shell. Larvae of this nematode were observed in the skeletal muscle. Other parasites were also recognized : Larval nematode, probably Porrocaecum sp., from a lymph-node ; Capillaria sp. from the urinary bladder ; Hymenolepis sp. from the small intestine ; and Sarcocystis sp. from the skeletal muscle

SOME NEMATODES OF THE JAPANESE SHREW MOLE, UROTRICHUS TALPOIDES TEMMINCK

Six specimens of the Japanese shrew mole, Urotrichus talpoides TEMMINCK, from central Japan were examined, and four nematodes were described : Spirura nipponensis n. sp. from the stomach, Capillaria himizu n. sp. from the urinary bladder, Rhabditis sp. from the stomach, and larval Rhabditoidea from the lungs

NUMERICAL IDENTIFICATION OF TEETH IN JAPANESE SHREW-MOLES, UROTRICHUS TALPOIDES AND DYMECODON PILIROSTRIS

Numerical determination of the teeth of two species of Japanese shrew-moles, Urotrichus talpoides and Dymecodon pilirostris (Talpidae, Insectivora), was based on the position of the premaxillo-maxillary suture, comparison of the dentitions of the two species with those of their relatives and the supernumerary tooth. The premaxillo-maxillary suture is situated between the fifth and sixth tooth anterior to the M1, and the fifth tooth anterior to the M1 was determined to be C both in the two species. The supernumerary tooth which appears in the gap between the third and fourth tooth anterior to the M1 of the lower jaw of Urotrichus talpoides was considered as a relic of pdl which seems to have been lost relatively recently in the evolution of this species. It was also shown that the first premolar of the upper jaw of the Urotrichus talpoides and the first premolars of the Dymecodon pilirostris are dihyodont. Retention of the dihyodont. first premolars in these species seems to be a prim itive character and is significant in determining the phylogenetical positions of these species

TOPOLOGICAL DISTRIBUTION OF MUSCLE SPINDLES IN THE HUMAN TONGUE AND ITS SIGNIFICANCE IN PROPRIOCEPTION

In order to obtain numerical data concerning the lingual muscle spindle distribution, the muscle spindles were histologically surveyed on the serial frontal and horizontal sections (stained by hematoxylin-eosin) from the apex to the radix of the tongue. On one side four hundred and sixty-six muscle spindles were counted in seven muscles, the superior longitudinal muscle containing 159 spindles, the genioglossus 80, the transverse 79, the styloglossus 75, the hyoglossus 37, the inferior longitudinal 22 and the vertical 14. The chondroglossus and the palatoglossus are devoid of the spindles. The question of whether the proprioceptive impulses from the lingual spindles lie in the hypoglossus nerve or in the lingual nerve has remained unsolved. This histological confirmation of the pathway and primary cell station of the lingual proprioceptive afferents is the subject in which the authors are greatly interested

MUSCLE SPINDLE SUPPLY TO THE SNOUT MUSCULATURE IN MOLES (TALPIDAE)

To define the anatomical background of the neuromuscular mechanism involved in the movement of the snout of the moles (Talpidae) the present histological study was carried out on the snout muscles of this family including the Japanese shrew-mole (Urotrichus talpoides), Japanese lesser shrew-mole (Dymecodon pilirostris) and Temminck’s mole (Mogera wogura). The snout musculature consists of five muscles: A) Zygomaticus major, B) Levator labii superioris, C) Levator alae nasi superioris, D) Levator alae nasi inferioris and E) Zygomaticus minor, the former two of which are the possessor of the muscle spindles and the latter three of which are not so, with the exception of the Zygomaticus minor having one spindle in the Japanese shrew-mole. Seventy-three spindles were counted on one side of the snout musculature in the Dymecodon pilirostris (12g in weight), 120 spindles in the Urotrichus talpoides (19g in weight) and the Mogera wogura (100g in weight). The snout musculature was 0.015g, 0.02g and 0.1g in weight, respectively. The number of spindles per milligram weight of the muscle was 4.9 in the Dymecodon, 6 in the Urotrichus and 1.2 in the Mogera. The density of the spindle distribution was much higher in the former two than in the latter one. Since the Dymecodon and Urotrichus actually search for food by moving their long snout vigorously over the ground and the Mogera, being a subterranean, searches for food by moving his snout not so vigorously under the ground, the pattern of the snout movement seems to be coincident with the morphological differentiation of the snout musculature and the density of the muscle spindle distribution in the moles (Talpidae)